This is a Renewal application for funding of an existing Occupational and Environmental Medicine (OEM) Residency at the University of Pennsylvania (UPENN) in existence since 1999. The program helps address the national shortage of OM physicians, their shortage in underserved areas, and the shortage of under-represented minority OM physicians. This shortage, addressed by the Institute of Medicine two decades ago, persists. We plan to continue this highly successful Competency Based Residency Training Program, directed primarily at experienced physicians making a mid-career change to full-time OEM practice, to prepare highly trained OM specialists, allowing them eligibility for the American Board of Preventive Medicine Certification Examination in Occupational Medicine (ABPM-OM). We intend to graduate one NIOSH supported resident each year from this 2-year training program, for a total of five NIOSH supported residents over the 5-year grant period. Successful applicants meet requirements of at least one (and usually more) ACGME-accredited clinical PGY-1 year, have started or completed the 5 core courses required by the ACGME, have completed or are actively enrolled in an MPH or masters level degree, and are in full-time OM practice at an approved clinical training site (CTS). Residents will complete at least 4 months of clinical training each year at their CTS. Concurrent with clinical work, residents undertake five subject-area rotations (SARs), each 2 months in length during the first year, and 6 SARs, each 1-month in length during the second year. A second year project that will culminate in a presentation at a local or national meeting and/or production of a manuscript is also a second year requirement. Competencies to be achieved are based on ACGME, ACOEM and select OEM competencies. Attainment of OEM Milestones will be required for graduation. Residents also undertake 8 graduate level courses related to OEM and PM over the 2-year period. The SARs, conducted at UPENN, are monthly 3-day intensive didactic training sessions. CTS and SAR directors are diplomats of the ABPM and national experts in the area they teach. The UPENN OEM Residency Program has successfully achieved objectives of training OEM physicians who are experts in the field, preparing them to carry out the purposes of the Occupational Safety and Health Act of 1970, as well as increasing the number of OEM physicians and underrepresented physicians. Graduates, 99 to date, have comprised 7% of new ABPM-OM diplomats since 2005 - more than any other US civilian program over this period, and score above means in the ABPM-OM Examination. Employed in industry, government, and academic centers, as well as in cities and rural areas, they report that the program met their needs and substantially increased their knowledge of OM. Most work in areas underserved by residency trained OEM physicians and are well-prepared to help conserve and restore the health of the workforce, promote worker health, productivity and well-being and recognize, control and prevent of occupational hazards.